1. The Field of the Invention
The present invention generally relates to eyeglasses and more specifically, to eyeglasses having interchangeable lens units and to eyeglasses easily adjusted to fit the user.
2. State of the Art
Glasses are well known utilitarian articles and are now items of apparel and of utility that come in various shapes and sizes to provide unique styles and lens types. U.S. Pat. No. 4,070,103 to Meeker discloses a spectacle combination which allows a person to change the frames of a pair of glasses to match any individual fashion or mood. The eyeglasses include a number of attachable pairs of one-piece lens rim covers of various colors, designs, shapes and materials. The lens rim covers are securely held in position by a lip, friction tape, magnetic strips or a snap-on type of friction fitting arrangement. The lens rim covers can be modified to change the shape of the lens, for instance, from the standard elliptical shape to a more high fashion octagonal square or rectangular shape. Additionally, tinted lens may be inserted in the individual pairs of lens rim covers in order to transform normal spectacles into light filters such as sunglasses.
Eyeglasses are typically held on the user's nose by the force of gravity and stabilized with stems, ears or extensions that are also sometimes called temples or temple pieces. The temples or temple pieces extend from the frame or rim near the temples rearward over the user's ears. The eyeglasses, however, are easily detached and can slip off or be lost when the wearer is involved in rigorous physical activity like bicycling, skiing, jogging, windsurfing, kayaking and the like.
A variety of eyeglass retainers have evolved that are or have been on the market. The retainers (e.g. the CHUMS brand, the EK brand) attach to the ends of the stems, extensions or temples and drape behind the head.
In order to fit eyeglasses to the head of a user, eyeglasses are typically adjusted by bending the stems, temples or ears and/or by bending a nose piece if a separate one is provided. Adjustments thus are made by bending which distorts the frames and nose piece which can lead to failure or a fit that cannot be easily adjusted based on the activity.
While some glasses are known to have interchangable lenses and lenses for a wide range of uses (e.g., ski goggles to deal with different light conditions), the lenses have open edges that expose them to damage and the user to whatever risks may be presented by the edges of the lenses. The lenses may be made from glass but also a wide range of other materials selected because they are break resistant, less prone to scratching or otherwise have preferred or desired features or characteristics.
There is no known eyeglass device which allows one to select lenses for use in a wide range of conditions including, for example, skiing and swimming while being adjustable and adapted for better retention on the head when in use.